Improving the Assisting Efficiency of Ankle Robot through Energy Harvesting of Achilles Tendon

2020 ◽  
Author(s):  
Guowei Huang ◽  
Zhihou Wang ◽  
Biao Liu ◽  
Zikang Zhou ◽  
Xiaoming Xian ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Achilles Tendon ◽  
Substantial Reduction ◽  
Metabolic Cost ◽  
Initial Result ◽  
Specific Power ◽  
Future Research ◽  
The Novel ◽  
Physiological Structure ◽  
Novel Design

Abstract Background The construction of lightweight robots poses one of the major challenges in the field of active robots since bearing the weight of an active robot significantly increases metabolic cost. However, few studies have achieved a substantial reduction in the robot weight. The primary reason is that the weight of the actuator, which comprises the main weight of the robot, is limited by the specific power, power requirements and assisting efficiency. Methods In this paper, we propose a new method that is utilizing the energy harvesting function of the Achilles tendon to improve the assistance efficiency of ankle robots to reduce the weight of the actuator and we design a novel ankle robot to test the validity of the method. The robot works with the ankle plantar flexor at 43%-60% of the gait cycle and has no other effects on the joints or the tendon of the lower limb. Healthy subjects were recruited to test the prototype in three conditions: free walking, power-on walking, and power-off walking. Data on the robot assisting power, metabolic cost and kinematics in different conditions were collected and analyzed. Result The results showed that the ankle robot can deliver forces at the controlled assistance timing. The average assisting power of 0.0650±0.0054 W/kg per leg resulted in an 8.7±8.1% and 19.0±6.4% net reduction in metabolic cost in power-on walking compared to free-walking and power-off walking, respectively. Conclusion Compared with the results of some of the best research, our initial result supports the validity of the method. This method can help to reduce the weight of active robots and the technical innovative method to determine the assistance timing more accurately and the novel design of the ankle robot can provide a reference for future research. To the best of our knowledge, this method is the first to use the human physiological structure to optimize the design of active robots.

scholarly journals Reduced Achilles Tendon Stiffness Disrupts Calf Muscle Neuromechanics in Elderly Gait

Gerontology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Rebecca L. Krupenevich ◽  
Owen N. Beck ◽  
Gregory S. Sawicki ◽  
Jason R. Franz
Keyword(s):  
Older Adults ◽  
Achilles Tendon ◽  
Metabolic Cost ◽  
Calf Muscle ◽  
Metabolic Energy ◽  
Joint Work ◽  
Tendon Stiffness ◽  
Age Related ◽  
Ankle Muscle ◽  
Metabolic Energy Expenditure

Older adults walk slower and with a higher metabolic energy expenditure than younger adults. In this review, we explore the hypothesis that age-related declines in Achilles tendon stiffness increase the metabolic cost of walking due to less economical calf muscle contractions and increased proximal joint work. This viewpoint may motivate interventions to restore ankle muscle-tendon stiffness, improve walking mechanics, and reduce metabolic cost in older adults.

scholarly journals Emerging Energy Harvesting Technology for Electro/Photo-Catalytic Water Splitting Application

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 142
Author(s):  
Jianfei Tang ◽  
Tianle Liu ◽  
Sijia Miao ◽  
Yuljae Cho
Keyword(s):  
Energy Harvesting ◽  
Water Splitting ◽  
Social Impact ◽  
Electrical Energy ◽  
Future Research ◽  
Daily Lives ◽  
Energy Applications ◽  
Sustainable Environment ◽  
Energy Technologies ◽  
Splitting System

In recent years, we have experienced extreme climate changes due to the global warming, continuously impacting and changing our daily lives. To build a sustainable environment and society, various energy technologies have been developed and introduced. Among them, energy harvesting, converting ambient environmental energy into electrical energy, has emerged as one of the promising technologies for a variety of energy applications. In particular, a photo (electro) catalytic water splitting system, coupled with emerging energy harvesting technology, has demonstrated high device performance, demonstrating its great social impact for the development of the new water splitting system. In this review article, we introduce and discuss in detail the emerging energy-harvesting technology for photo (electro) catalytic water splitting applications. The article includes fundamentals of photocatalytic and electrocatalytic water splitting and water splitting applications coupled with the emerging energy-harvesting technologies using piezoelectric, piezo-phototronic, pyroelectric, triboelectric, and photovoltaic effects. We comprehensively deal with different mechanisms in water splitting processes with respect to the energy harvesting processes and their effect on the water splitting systems. Lastly, new opportunities in energy harvesting-assisted water splitting are introduced together with future research directions that need to be investigated for further development of new types of water splitting systems.

Calculation and Measurement of the Stiffness and Damping Coefficients for a Low Impedance Hydrodynamic Bearing

1997 ◽  
Vol 119 (1) ◽  
pp. 57-63 ◽  
Author(s):  
M. J. Goodwin ◽  
P. J. Ogrodnik ◽  
M. P. Roach ◽  
Y. Fang
Keyword(s):  
Experimental Data ◽  
Dynamic Stiffness ◽  
Perturbation Technique ◽  
The Novel ◽  
Oil Film ◽  
Hydrodynamic Bearing ◽  
Damping Coefficients ◽  
Stiffness And Damping ◽  
Film Stiffness ◽  
Novel Design

This paper describes a combined theoretical and experimental investigation of the eight oil film stiffness and damping coefficients for a novel low impedance hydrodynamic bearing. The novel design incorporates a recess in the bearing surface which is connected to a standard commercial gas bag accumulator; this arrangement reduces the oil film dynamic stiffness and leads to improved machine response and stability. A finite difference method was used to solve Reynolds equation and yield the pressure distribution in the bearing oil film. Integration of the pressure profile then enabled the fluid film forces to be evaluated. A perturbation technique was used to determine the dynamic pressure components, and hence to determine the eight oil film stiffness and damping coefficients. Experimental data was obtained from a laboratory test rig in which a test bearing, floating on a rotating shaft, was excited by a multi-frequency force signal. Measurements of the resulting relative movement between bearing and journal enabled the oil film coefficients to be measured. The results of the work show good agreement between theoretical and experimental data, and indicate that the oil film impedance of the novel design is considerably lower than that of a conventional bearing.

scholarly journals The movement ecology of seagrasses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140878 ◽  
Author(s):  
Kathryn McMahon ◽  
Kor-jent van Dijk ◽  
Leonardo Ruiz-Montoya ◽  
Gary A. Kendrick ◽  
Siegfried L. Krauss ◽  
...  
Keyword(s):  
Life History ◽  
Clonal Growth ◽  
Movement Ecology ◽  
Future Research ◽  
The Novel ◽  
Long Distance ◽  
Spatial And Temporal Scales ◽  
Life History Stages ◽  
Research Areas ◽  
Time Movement

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

Introduction and Preliminary Investigation of Buoyancy Assisted Robots That Are Cheap, Safe, and Will Never Fall Down

2021 ◽  
Author(s):  
Matthew David Williams ◽  
Dennis Hong
Keyword(s):  
Genetic Algorithm ◽  
Preliminary Analysis ◽  
Preliminary Investigation ◽  
Research Work ◽  
Legged Robots ◽  
Dynamical Analysis ◽  
Future Research ◽  
The Novel ◽  
Drag Forces ◽  
New Family

Abstract We introduce and define a new family of mobile robots called BAR (Buoyancy Assisted Robots) that are cheap, safe, and will never fall down. BARs utilize buoyancy from lighter-than-air gases as a way to support the weight of the robot for locomotion. A new BAR robot named BLAIR (Buoyant Legged Actuated Inverted Robot) whose buoyancy is greater than its weight is also presented in this paper. BLAIRs can walk “upside-down” on the ceiling, providing unique advantages that no other robot platforms can. Unlike other legged robots, the mechanics of how BARs walk is fundamentally different. We also perform a preliminary investigation for BARs. This includes comparing safety, cost, and energy consumption with other commercially available robots. Additionally, the preliminary investigation also includes analyzing previous works relating to BARs. A dynamical analysis is performed on the novel robot BLAIR. This is presented to show the impacts of buoyant and drag forces on BLAIRs. Preliminary analysis with the prevalence of drag is presented with simulations using a genetic algorithm and simulations. Results show that BARs with different mechanisms prefer different styles of walking gaits such as prancing or skipping. This work lays the foundation for future research work on the gaits for BARs.

scholarly journals A novel flexible tool with rotary ultrasonic spindle for fine grinding of tungsten carbide

2018 ◽  
Vol 185 ◽  
pp. 00018
Author(s):  
Albert Wen-Jeng Hsue ◽  
Yi-Zhong Zheng
Keyword(s):  
Tungsten Carbide ◽  
The Novel ◽  
Machining Processes ◽  
Flexible Tool ◽  
Operational Conditions ◽  
Cnc Grinding ◽  
Grinding Conditions ◽  
Novel Design ◽  
Conventional Machining ◽  
Tungsten Steel

Tungsten carbide is a typical difficult-to-cut material by conventional machining processes. In this paper, a novel design of flexible abrasives tool combined with a rotary ultrasonic machining (RUM) spindle is conducted to reduce the labor force significantly. The newly designed flexibility of tool-tip is aimed at preventing overcutting from the CNC grinding. The grinding conditions with resulted surface morphology of the tungsten steel were investigated through Taguchi design of experiment and ANOVA analysis. The machining capability of the novel flexible tool is compared with conventional tools through specific grinding paths under proper operational conditions.

Why Do So Few Consumers Use Health Care Quality Report Cards? A Framework for Understanding the Limited Consumer Impact of Comparative Quality Information

2018 ◽  
Vol 76 (5) ◽  
pp. 515-537 ◽  
Author(s):  
Neeraj Bhandari ◽  
Dennis P. Scanlon ◽  
Yunfeng Shi ◽  
Rachel A. Smith
Keyword(s):  
Health Care Quality ◽  
Care Quality ◽  
Report Cards ◽  
Quality Information ◽  
The Novel ◽  
Cognitive Limitations ◽  
Provider Quality ◽  
The Media ◽  
New Generation ◽  
Novel Design

Despite growing investment in producing and releasing comparative provider quality information (CQI), consumer use of CQI has remained poor. We offer a framework to interpret and synthesize the existing literature’s diverse approaches to explaining the CQI’s low appeal for consumers. Our framework cautions CQI stakeholders against forming unrealistic expectations of pervasive consumer use and suggests that they focus their efforts more narrowly on consumers who may find CQI more salient for choosing providers. We review the consumer impact of stakeholder efforts to apply the burgeoning knowledge of consumers’ cognitive limitations to the design and dissemination of the new generation of report cards; we conclude that while it is too limited to draw firm conclusions, early evidence suggests consumers are responding to the novel design and dissemination strategies. We find that consumers continue to have difficulty accessing reliable report cards, while the media remains underused in the dissemination of report cards.

scholarly journals A Novel Kartogenin-Releasing Polymer Scaffold Promotes Wounded Rat Achilles Tendon Enthesis Healing

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0053
Author(s):  
Jianying Zhang ◽  
Daibang Nie ◽  
Guangyi Zhao ◽  
Susheng Tan ◽  
MaCalus Hogan ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Saline Group ◽  
Future Research ◽  
Dependent Manner ◽  
Polymer Scaffold ◽  
Normal Medium ◽  
Post Surgery ◽  
Tendon Stem Cells

Category: Hindfoot Introduction/Purpose: Entheses have a special fibrocartilage transition zone where tendons and ligaments attach to bone. Enthesis injury is very common, and the reattachment of tendon to bone is a great challenge because healing takes place between a soft tissue (tendon) and a hard tissue (bone). We have now developed a kartogene (KGN)-containing polymer scaffold (KGN-P) that can precisely deliver KGN to damaged enthesis area. The effects of the KGN-containing polymer on the healing of wounded TBJ were investigated in vitro and in vivo. Methods: The proliferation and chondrogenesis of rat Achilles tendon stem cells (TSCs) grown in four conditions were measured: normal medium (Control); normal medium with 100 nM KGN (KGN); lysine diisocyanate (LDI)-glycerol scaffold with normal medium (LDI-P); LDI-glycerol-KGN scaffold with normal medium (KGN-P).A wound (1 mm) was created on each hind leg Achilles enthesis of all 8 rats (3 months old). The wounds were then treated either with 10 ul saline (Wound); or 10 ul of 10 uM KGN (KGN); or LDI polymer scaffold (LDI-P); or KGN-containing polymer scaffold (KGN-P). The rats were sacrificed on day 15 and 30 post-surgery, and their Achilles entheses were collected for gross inspection and histochemical analysis. Results: KGN-containing polymers have sponge-like structures (Fig. 1A-D), and release KGN in a time- and temperature-dependent manner (Fig. 1E). KGN-P scaffold induced chondrogenesis of TSCs (Fig. 2D, 2H) without changing cell proliferation (Fig. 2I), and enhanced fibrocartilage-like tissue formation (Fig. 3E). KGN (Fig. 3C) and LDI-P (Fig. 3D) treated groups exhibited unhealed wound areas as in saline group (Fig. 3B). Finally, KGN-P and KGN treated rat TSCs underwent chondrogenesis by upregulating collagen II, aggrecan, and SOX-9 expression (Fig. 3F). Conclusion: Our results showed that KGN-containing polymer scaffold enhanced wounded enthesis healing by inducing TSC chondrogenesis and promoting the formation of the fibrocartilage in the wound site. The KGN-P may be used for regeneration of wounded entheses in clinical settings. Future research will focus on optimizing KGN concentration and releasing rate in the polymer scaffold during enthesis healing.

Effects of lipotoxicity on a novel insulin-secreting human pancreatic β-cell line, 1.1B4

2013 ◽  
Vol 394 (7) ◽  
pp. 909-918 ◽  
Author(s):  
Srividya Vasu ◽  
Neville H. McClenaghan ◽  
Jane T. McCluskey ◽  
Peter R. Flatt
Keyword(s):  
Mrna Expression ◽  
Cell Line ◽  
Molecular Mechanisms ◽  
Endoplasmic Reticulum Stress Response ◽  
Future Research ◽  
The Novel ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Expression Of Genes ◽  
Cellular Ca

Abstract The novel insulin-secreting human pancreatic β-cell line, 1.1B4, demonstrates stability in culture and many of the secretory functional attributes of human pancreatic β-cells. This study investigated the cellular responses of 1.1B4 cells to lipotoxicity. Chronic 18-h exposure of 1.1B4 cells to 0.5 mm palmitate resulted in decreased cell viability and insulin content. Secretory responses to classical insulinotropic agents and cellular Ca2+ handling were also impaired. Palmitate decreased glucokinase activity and mRNA expression of genes involved in secretory function but up-regulated mRNA expression of HSPA5, EIF2A, and EIF2AK3, implicating activation of the endoplasmic reticulum stress response. Palmitate also induced DNA damage and apoptosis of 1.1B4 cells. These responses were accompanied by increased gene expression of the antioxidant enzymes SOD1, SOD2, CAT and GPX1. This study details molecular mechanisms underlying lipotoxicity in 1.1B4 cells and indicates the potential value of the novel β-cell line for future research.

scholarly journals Electro-Active Paper as a Flexible Mechanical Sensor, Actuator and Energy Harvesting Transducer: A Review

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3474 ◽  
Author(s):  
Asif Khan ◽  
Faisal Raza Khan ◽  
Heung Soo Kim
Keyword(s):  
Energy Harvesting ◽  
Polyvinylidene Fluoride ◽  
Mechanical Vibration ◽  
Hybrid Nanocomposites ◽  
Vibration Sensor ◽  
Vibration Energy ◽  
Future Research ◽  
Energy Scavenging ◽  
Vibration Energy Harvester ◽  
Bending Actuator

Electro-active paper (EAPap) is a cellulose-based smart material that has shown promising results in a variety of smart applications (e.g., vibration sensor, piezo-speaker, bending actuator) with the merits of being flexible, lightweight, fracture tolerant, biodegradable, naturally abundant, cheap, biocompatible, and with the ability to form hybrid nanocomposites. This paper presents a review of the characterization and application of EAPap as a flexible mechanical vibration/strain sensor, bending actuator, and vibration energy harvester. The working mechanism of EAPap is explained along with the various parameters and factors that influence the sensing, actuation, and energy harvesting capabilities of EAPap. Although the piezoelectricity of EAPap is comparable to that of commercially available polyvinylidene fluoride (PVDF), EAPap has the preferable merits in terms of natural abundance and ample capacity of chemical modification. The article would provide guidelines for the characterization and application of EAPap in mechanical sensing, actuation, and vibration energy scavenging, along with the possible limitations and future research prospects.

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